Suggest you take a ride to the grocery store called Hi Lo....there is a good selection of wines there that are OK if you arent a wine snob . Yellowtail as mentioned and any of the Concha Y Toro wines are decent as well. I don't purchase wine at the little shops on the beach and road since its hard to tell how long they have been sitting there for (usually in the sun all day too).
If you order fish in most restaurants, head and tail arent usually included! BUT...if you are fish lovers, suggest you try some from vendors too, especially if they have "fry fish", head and tail on but the best ever.